This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A356543 #13 Aug 30 2023 02:00:46
%S A356543 1,2,2,4,2,12,2,34,38,138,2,1546,2,5106,15698,54274,2,889314,2,
%T A356543 5689090,25448258,39917826,2,2486196610,207360002,6227024898,
%U A356543 131683574018,215393466370,2,14769495662082,2,86475697160194,1593350982706178,355687428161538,648227266560002
%N A356543 a(n) = Sum_{d|n} (d!)^(n/d-1).
%F A356543 G.f.: Sum_{k>=1} x^k/(1 - k! * x^k).
%F A356543 If p is prime, a(p) = 2.
%t A356543 a[n_] := DivisorSum[n, (#)!^(n/# - 1) &]; Array[a, 35] (* _Amiram Eldar_, Aug 30 2023 *)
%o A356543 (PARI) a(n) = sumdiv(n, d, d!^(n/d-1));
%o A356543 (PARI) my(N=40, x='x+O('x^N)); Vec(sum(k=1, N, x^k/(1-k!*x^k)))
%Y A356543 Cf. A087909, A342628, A356541.
%K A356543 nonn
%O A356543 1,2
%A A356543 _Seiichi Manyama_, Aug 11 2022